Personally, I wouldn't kick a modern clone out of bed for eating crackers. If, on the other hand, I were spending serious money on a custom "classic" build I would prefer it to be done on an original.
The argument of clone vs. original can be illustrated by the replica car movement too. Is a Factory 5 roadster really a 427 Cobra? Same white knuckled performance?- check. Same styling?- check. Same car?- nope. Cost a small fraction of an original 427?- check. (My BIL built a Factory 5, and he has scared me silly with it.)